[NFC] Extend AddressInitializationWalker.findSingleInitializer

Handle applies that reassign the lifetime of their operand vs. the value of their operand.

Author: atrick

SwiftCompilerSources/Sources/Optimizer/Utilities/AddressUtils.swift

@@ -279,7 +279,7 @@ extension AccessBase {
  default:
  return nil
  }
- return AddressInitializationWalker.findSingleInitializer(ofAddress: baseAddr, context: context)
+ return AddressInitializationWalker.findSingleInitializer(ofAddress: baseAddr, requireFullyAssigned: .value, context)
  }
 }
 
@@ -311,25 +311,29 @@ extension AccessBase {
 // modification of memory.
 struct AddressInitializationWalker: AddressDefUseWalker, AddressUseVisitor {
  let baseAddress: Value
+ let requireFullyAssigned: IsFullyAssigned
  let context: any Context
 
  var walkDownCache = WalkerCache<SmallProjectionPath>()
 
  var isProjected = false
  var initializer: AccessBase.Initializer?
 
- static func findSingleInitializer(ofAddress baseAddr: Value, context: some Context)
+ static func findSingleInitializer(ofAddress baseAddr: Value, requireFullyAssigned: IsFullyAssigned,
+ _ context: some Context)
  -> AccessBase.Initializer? {
 
- var walker = AddressInitializationWalker(baseAddress: baseAddr, context)
+ var walker = AddressInitializationWalker(baseAddress: baseAddr, requireFullyAssigned, context)
  if walker.walkDownUses(ofAddress: baseAddr, path: SmallProjectionPath()) == .abortWalk {
  return nil
  }
  return walker.initializer
  }
 
- private init(baseAddress: Value, _ context: some Context) {
+ private init(baseAddress: Value, _ requireFullyAssigned: IsFullyAssigned, _ context: some Context) {
+ assert(requireFullyAssigned != .no)
  self.baseAddress = baseAddress
+ self.requireFullyAssigned = requireFullyAssigned
  self.context = context
  if let arg = baseAddress as? FunctionArgument {
  assert(!arg.convention.isIndirectIn, "@in arguments cannot be initialized")
@@ -392,7 +396,15 @@ extension AddressInitializationWalker {
 
  mutating func appliedAddressUse(of operand: Operand, by apply: FullApplySite)
  -> WalkResult {
- if operand.isAddressInitialization {
+ switch apply.fullyAssigns(operand: operand) {
+ case .no:
+ break
+ case .lifetime:
+ if requireFullyAssigned == .value {
+ break
+ }
+ fallthrough
+ case .value:
  return setInitializer(instruction: operand.instruction)
  }
  guard let convention = apply.convention(of: operand) else {